Alternative rock (also called alternative music, alt rock or simply alternative) is a genre of rock music that emerged from the independent music underground of the 1980s and became widely popular by the 1990s. Although the term was most commonly associated in its commercial heyday with a loud, distorted guitar sound, its original meaning was broader, referring to a generation of musicians unified by their collective debt to either the musical style, or simply the independent, D.I.Y. ethos of punk rock, which in the late 1970s laid the groundwork for alternative music.[1] At times, "alternative" has been used as a catch-all description for music from underground rock artists that receives mainstream recognition, or for any music, whether rock or not, that is seen to be descended from punk rock (including some examples of punk itself, as well as New Wave, and post-punk).Wikipedia

RockRock music is a genre of popular music that originated as "rock and roll" in 1950s America and developed into a range of different styles in the 1960s and later, particularly in the United Kingdom and the United States.[1][2][3] It has its roots in 1940s' and 1950s' rock and roll, itself heavily influenced by rhythm and blues and country music. Rock music also drew strongly on a number of other genres such as blues and folk, and incorporated influences from jazz, classical and other musical sources.Wikipedia